Aspirin Desensitization

Introduction
The term "aspirin-sensitive asthma" (also known as "aspirin triad" or "Samter's Triad") is a complex medical condition that causes patients to have asthma, chronic sinusitis, and nasal polyps. Typically, patients who have aspirin-sensitive asthma cannot take aspirin or aspirin-containing products since aspirin can cause severe asthma attacks, runny nose, facial/chest/back flushing, as well as swelling in the throat or skin.

Aspirin sensitive asthma occurs in <1% of patients and is more common in women than men. Typically, patients are in their 30s when they notice the onset of this condition. Patients who have severe asthma are more likely to be aspirin sensitive than patients with mild asthma. Similarly, patients with polyps and asthma are more likely to be aspirin sensitive than are patients with just nasal polyps.

Pathophysiology
Why an individual becomes sensitive to aspirin is not completely understood. Some scientists believe that patients develop an "allergy" to aspirin; however, the allergy to aspirin is not the same as allergies to dust mites, cats, dogs, or pollen. Others believe sensitivity to aspirin results from a problem in certain chemical pathways that produce inflammatory chemicals in the body. Some believe there are genetic causes.

diagnosis
A thorough history and examination is required to diagnose patients with aspirin sensitivity. Patients with severe asthma, chronic sinusitis, nasal polyps and previous problems taking aspirin or non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, Advil, Motrin, Aleve and drugs such as those may have aspirin sensitivity.

Unfortunately, there is no blood test that can diagnose this condition. Your immunologist or allergist may perform what is called a "provocation" test to determine if you are sensitive to aspirin. This provocation test is performed when you are given a small dose of aspirin to determine your reaction. Certain laboratory tests following the provocation may also be administered. This has to be done in a very controlled setting, so that any reaction you have can be treated appropriately.

treatment
Treatment of aspirin sensitivity begins with education and establishing a list of drugs that contain aspirin or NSAIDs. In patients with rhinosinusitis (another term for sinusitis) and nasal polyps, endoscopic sinus surgery may help certain patients whose asthma is worsened by their nasal problems. After surgery is performed, it is often helpful to perform "aspirin desensitization."

Aspirin desensitization is usually performed with oral administration of aspirin (taking aspirin by mouth). This begins at very small doses until a patient is able to tolerate 650mg of aspirin. (The typical amount in one tablet of aspirin is 325mg). The best results in some studies have been seen when patients are taking up to 1300mg daily (650mg twice daily). Some studies suggest that lower doses may be as effective.

Patients should plan the timing of aspirin desensitization carefully, as aspirin is known to have side effects of allowing patients to bleed more easily and make blood clots less effectively. If patients know they are going to need surgery (whether sinus related or not) it is better to wait until after that surgery is completed before starting desensitization. If patients who have undergone aspirin desensitization need surgery in the future, it is likely they may have to stop the aspirin to decrease bleeding risk, and then start over from the beginning once they have completed surgery.